Function of a Raymarine Seatalk 2 Terminator

[Slipstream 34]

I am in the process of fitting a remote keyboard E55061 to an E80 classic. The wiring diagram uses junction boxes to connect the keyboard. Each junction box has a "Terminator" plugged in. I was planning on hard-wiring the keyboard to a seatalk 2 cable plugged into the E80. Are there any problems hard-wiring it without the "Terminators" ?

Thanks.

 

[Talulah]

It won't work.
The Seatalk 2 network was an early version of the NMEA2000 network. The terminators are needed at each end of the network.

 

[AngusMcDoon]

It won't work.
The Seatalk 2 network was an early version of the NMEA2000 network. The terminators are needed at each end of the network.

Stops the signal bouncing back along the wire when it reaches the open circuit of an unterminated wire. A terminator is just a resistor which absorbs the signal's energy stopping the bounce. The bounced signal would otherwise interfere with the following bit of the signal. Think of a long duct full of water and you are at one end making waves which travel along the duct. If there's a vertical wall at the end the waves bounce off it and mess up the subsequent waves travelling down the duct. However, if you had a nice shelving sandy beach at the far end the waves would not bounce and there would be no interference.

 

[Slipstream 34]

Thanks Talulah and Angus, much appreciated.

 

[vissers brian]

I am.in this very same.situation ,i have tried putting a 120 ohm.resistor at the keyboard (inside across the data leads) also.up at the connector at the E 80 MFD, no luck. How ever my MFD diagnostics show a stream of sea talk NG frames even with nothing connected to the sea talk 2 ( NG ) port. Did you get it to work ? i dont have the backbone cables or T s . I have a connector and cable straight out the MFD wired to the keyboard with 12v injected at KB. My scope shows data on data leads when keys activated.

 

[Slipstream 34]

I am.in this very same.situation ,i have tried putting a 120 ohm.resistor at the keyboard (inside across the data leads) also.up at the connector at the E 80 MFD, no luck. How ever my MFD diagnostics show a stream of sea talk NG frames even with nothing connected to the sea talk 2 ( NG ) port. Did you get it to work ? i dont have the backbone cables or T s . I have a connector and cable straight out the MFD wired to the keyboard with 12v injected at KB. My scope shows data on data leads when keys activated.

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